UK online casinos operate under strict rules set by the UK Gambling Commission...

https://www.jelly-bookmarks.win/uk-online-casinos-operate-under-tight-oversight-from-the-uk-gambling

UK online casinos operate under strict rules set by the UK Gambling Commission to ensure fairness and transparency. For example, many games offer around 96% return to player, meaning most bets are returned as winnings over time